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Aquifers switched from confined to semiconfined by earthquakes
Author(s) -
Shi Zheming,
Wang Guangcai
Publication year - 2016
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2016gl070937
Subject(s) - aquifer , geology , groundwater , permeability (electromagnetism) , aquifer properties , artesian aquifer , specific storage , hydraulic conductivity , seismology , geotechnical engineering , soil science , groundwater recharge , membrane , biology , soil water , genetics
Earthquake‐induced aquifer parameter changes (e.g., permeability and hydraulic diffusivity) have been documented in many studies. However, changes in the confinement of an aquifer from confined to semiconfined following an earthquake have not been reported. Here we focus on the tidal response of the water level in four wells following the 2008 Wenchuan M w 7.9 and 2013 Lushan M w 6.6 earthquakes to show that earthquakes can change confined aquifers to semiconfined aquifers by reopening of preexisting vertical fractures (and later healing). This study has important implications because a switch from confined to semiconfined means a change of vertical hydraulic connection, which may affect the vulnerability of an aquifer, the integrity of underground waste repositories, and the safety of groundwater supplies.